The invention relates to an apparatus for fusing a solid layer of electrically conductive material and for producing a homogeneous molten stream running from a ceramic-free crucible.
U.S. Pat. No. 5,272,718 discloses a method for forming a molten stream by means of a funnel flanged to a larger melting tank in which the molten material is situated. The funnel is divided into liquid-cooled metal segments, and a coil supplied with alternating current surrounds the funnel and heats the melt in the funnel by induction. This known method produces a molten metal stream that will be as thin as possible while avoiding the risk of solidification.
U.S. Pat. No. 4,738,713 discloses a crucible for the ceramic-free melting of reactive metals or metal alloys, consisting of a plurality of water-cooled palisades of metal, which are all connected together electrically and form narrow gaps with one another. The crucible formed by the palisades is surrounded by an induction coil permitting the charge to be melted, and the crucible and coil are disposed in a vacuum tank. This cold crucible permits the slag-free fusion of reactive metals of high purity.
U.S. Pat. No. 5,084,091 discloses a slotted crucible of similar configuration for melting titanium particles. The crucible is provided with a bottom spout permitting the molten metal to flow out for the purpose of spraying it.
Lastly, U.S. Pat. No. 4,762,553 discloses a powder spraying apparatus for the purpose of levitation melting, charges on the order of 2 kg. The crucible is surrounded by a first induction coil and the bottom spout is held by a second coil serving to aim the stream; each coil is provided with its own power supply. A gas nozzle at the bottom end of the spout enables the molten metal to be atomized.